The present invention generally relates to a rotorcraft apparatus and, more specifically, to an unmanned rotorcraft apparatus employing a unique combination of anti-torque, modular construction, aeromechanics, and system/sub-system integration.
Anti-torque has been traditionally provided by tail rotors, fan-tails, and, more recently, by the NOTAR(copyright) thrust vectoring system. Tail rotors and fan-tails are operated using power from the main engine, thus resulting in a loss in efficiency of the main engine""s overall output to the main rotor. Moreover, these conventional systems present vulnerability problems with the exposed rotating machinery. Not only do these supplemental rotors add to the size of the rotorcraft, but they also pose additional mechanical and safety issues.
Alternatives to these anti-torque systems include a dual counter-rotating main rotors, such as installed on the Russian Ka-25, or a tandem installation of rotors, as installed on the Boeing CH-47 Chinook. These approaches, however, result in large, mechanically complex aircraft which, while suitable for heavy lift operations, are poor choices for smaller, low cost unmanned systems.
It is often necessary to install apertures in aircraft to provide for navigation, communications, and target identification and designation. This is often accomplished using optical equipment, such as a camera or laser ranger. Conventional helicopter fuselages offer no solution for the lack of surface area for aperture installation facing the desired directions. Rotorcraft are frequently required to add surfaces, protuberances, or other drag producing features to accommodate apertures. In the case of electro-optical sensors with forward field-of-view capability, huge turret structures, such as those installed on the AH-64 Apache and the RAH-66 Comanche are common.
Conventional rotorcraft achieve mission flexibility by incorporating large internal volumes with optional externally mounted pods and weapons. These approaches simultaneously add drag, increase vulnerability, and force the aircraft to be larger than needed for individual missions as the internal spaces must be sized for all desired combinations.
As can be seen, there is a need for an improved unmanned rotorcraft apparatus that has the combination of a simple anti-torque design, a modular construction to allow for mission flexibility, and excellent aeromechanics. The absence of a crew enables significant departure from conventional overall vehicle integration approaches.
In one aspect of the present invention, a rotorcraft comprises a central core structure having an engine; a main rotor driven by the engine; a plurality of arms attached to the central core structure, each of the plurality of arms having a storage region therein; and tip jets at a distal end of each of the plurality of arms wherein an air stream passing through select tip jets provide anti-torque and attitude control for the rotorcraft.
In another aspect of the present invention, a tripodal unmanned rotorcraft comprises a central core structure having an engine; a main rotor driven by the engine; first, second, and third arms attached to the central core structure, each of the first, second and third arms having a storage region therein; tip jets at a distal end of each of the first, second and third arms wherein an air stream passing through select tip jets provide anti-torque and attitude control for the rotorcraft; tip jet plumbing for supplying the air stream to the tip jets from an engine bleed; and a compressor bleed plenum for collecting and evenly distributing the engine bleed to the tip jet plumbing.
In yet another aspect of the present invention, a tripodal unmanned rotorcraft for delivering a payload to a remote location, comprises a central core structure having an engine; a main rotor driven by the engine; first, second, and third arms attached to the central core structure, each of the first, second and third arms being equally spaced about the central core structure and having a storage region therein for containing the payload; tip jets at a distal end of each of the first, second and third arms wherein an air stream passing through select tip jets provide anti-torque, attitude control, and directional maneuvering for the rotorcraft; and tip jet plumbing for supplying the air stream to the tip jets from an engine bleed; a compressor bleed plenum for collecting and evenly distributing the engine bleed to the tip jet plumbing; and an internal fan/rotor in the central core structure rotating in a direction opposite that of the rotor to provide an anti-torque element as well as an additional cooling air flow to the central core structure.
In a further aspect of the present invention, a tripodal modular unmanned rotorcraft comprises a central core structure having an engine; a main rotor driven by the engine; first, second, and third arms detachably connected to the central core structure, each of the first, second and third arms being equally spaced about the central core structure and having a storage region therein; landing gear located at a distal end of each of the first, second and third arms; tip jets at a distal end of each of the first, second and third arms wherein an air stream passing through select tip jets provide anti-torque, attitude control, and directional maneuvering for the rotorcraft; tip jet plumbing for supplying the air stream to the tip jets from an engine bleed; a compressor bleed plenum for collecting and evenly distributing the engine bleed to the tip jet plumbing; and an internal rotor/fan in the central core structure, rotating opposite that of the rotor, to provide an anti-torque element as well as an additional cooling air flow to the central core structure.
In still a further aspect of the present invention, a method for making a rotorcraft, comprises vertically mounting an engine in a central core structure of the rotorcraft, the engine driving a main rotor; detachably connecting a first arm, a second arm and a third arm to the central core structure, each of the first arm, the second arm and the third arm having a storage region therein; providing means for generating pressurized air in the central core; delivering the pressurized air to tip jets located at a distal end of each of the first arm, the second arm, and the third arm, whereby when the pressurized air passes through the tip jets, anti-torque, attitude control, and directional maneuvering is provided for the rotorcraft.